Milling cutter

Abstract

A milling cutter consists of a shaft 10, a cutter plate 12 and a screw bolt 14 by means of which the cutter plate 12 is detachably fastened at the front end of the shaft 10. The latter has a recess in the front face thereof. The recess is defined by three planar side faces leaving a peripheral gap between each pair thereof. The cutter plate substantially formed triangularly is fitted in the recess for being inmovable in a radial plane. Protrusions 30 of the cutter plate protrude through the gaps and are provided with a cutting edge respectively.

I claim: 
     
       1. A milling cutter comprising a shaft and a cutter plate, the cutter plate provided with a central bore and with a plurality of peripherally spaced teeth concentrically arranged with respect to the bore, a screw or a screw bolt extending through said central bore in said cutter plate and into a tap hole coaxially arranged in the front end of the shaft for detachably fastening the cutter plate at the front face of the shaft; the shaft provided with a recess at the front side thereof, the periphery of the recess defined by three planar inside surfaces coinciding with the sides of an equilateral triangle symmetrically arranged with respect to the central bore, a gap provided between each pair of adjacent planar inside surfaces on the shaft front end diameter, the cutter plate provided with three planar outside surfaces, coinciding with the sides of said equilateral triangle, one tooth formed between extensions of each pair of planar outside surfaces of the cutter plate, the cutter plate fitted in the recess such that each one of said three outside surfaces of the cutter plate contacts one of said three inside surfaces of the recess thereby completely filling up the recess and only the teeth protruding outwards through said gaps. 
     
     
       2. A milling cutter as claimed in claim 1, wherein one extension of each planar outside surface of the cutter plate is in a straight line with that planar outside surface and forms the rearward side of one tooth and wherein the extension at the other end of that planar outside surface is concavely shaped and forms a cutting face of another tooth. 
     
     
       3. A milling cutter as claimed in claim 2, wherein the outer end of the concave cutting face of the tooth approaches tangentially outwards an imaginary radial line of the cutter plate. 
     
     
       4. A milling cutter as claimed in claim 2, wherein the inner end of the concave cutting face and the outside end of the adjacent planar outside surface of the cutter plate meet one another on the shaft front end diameter. 
     
     
       5. A milling cutter as claimed in claim 1, wherein the depth of the recess is substantially equal with the constant thickness of the cutter plate in the area of the shaft front end diameter.